MOVEMENT OF SODIUM AND POTASSIUM IONS DURING NERVOUS ACTIVITY
This extract was created in the absence of an abstract.
Excerpt
Experiments with the giant nerve fibres of squids and cuttlefish show that electrical activity is associated with characteristic movements of the sodium and potassium ions. When an impulse is conducted along one of these fibres sodium ions move inwards from the more concentrated solution outside the fibre while potassium ions move outwards from the more concentrated solution inside the fibre. Measurements with tracers, such as those made by Rothenberg (1950), Keynes (1951), Keynes and Lewis (1951) and Grundfest and Nachmansohn (1950) give reasonably consistent figures for the movements of sodium and potassium ions during electrical activity. At room temperature it appears that about 4 μμmol of sodium ions enters 1 sq. cm of membrane during one impulse and that a corresponding quantity of potassium ions leaves the fibre. Similar changes probably occur in many other excitable tissues, but in crab muscle (Fatt and Katz, 1952) or in the ‘Et fibres’
